Couples take part in the “Love and Challenge Marathon” in Hanoi, Vietnam, 16 August 2015. Fifty couples, who are going to get married, participated in the event which is held the fifth time. This year, the winners of the marathon received a honeymoon trip to Malaysia. (Photo by Luong Thai Linh/EPA)

“Tough Times for Orangutans”. Nature, first prize stories. Tim Laman, USA. Location: West Kalimantan, Indonesia. A Bornean orangutan climbs over 30 meters up a tree in the rain forest of Gunung Palung National Park, West Kalimantan, Indonesia, August 12, 2015. The lives of wild orangutans are brought to light. Threats to these orangutans from fires, the illegal animal trade and loss of habitat due to deforestation have resulted in many orphan orangutans ending up at rehabilitation centers. (Photo by Tim Laman/World Press Photo Contest)

Macaque monkeys crowd together in their cage at a monkey farm on February 3, 2016 in Xinye county, Henan province, China. The area boasts a centuries-long and lucrative history of raising and training monkeys for performance. In Xinye, villagers are seeing an increase in business with the lunar calendar's “Year of the Monkey”. Farmers say most of the monkeys are bred and raised for domestic zoos, circuses, and performing groups, but add that some are also sold for medical research in China and the United States. Despite the popularity of the tradition, critics contend the training methods and conditions constitute animal cruelty. (Photo by Kevin Frayer/Getty Images)

A Nepalese Gurung community woman, wearing traditional attire, prepares to participate in a parade to mark their New Year known as “Tamu Loshar” in Kathmandu, Nepal, Friday, December 30, 2016. The indigenous Gurungs, also known as Tamu, are celebrating the advent of the year of the bird. (Photo by Niranjan Shrestha/AP Photo)

Chacha, the male chimp, screams at a worker in Sendai, northern Japan, Thursday, April 14, 2016 after fleeing from a zoo. The chimpangzee tried desperately to avoid being captured by climbing an electric pole. Chacha was on the loose nearly two hours Thursday after it disappeared from the Yagiyama Zoological Park in Sendai, the city that's hosting finance ministers from the Group of Seven industrialized nations in May. (Photo by Kyodo News via AP Photo)

Professional wrestler “p*ssy Willow” overpowers client Wilfred during their BDSM wrestling session at The Submission Room session wrestling and BDSM gym in Seven Sisters, on December 12, 2016 in London, England. (Photo by Susannah Ireland/Barcroft Images)

A policer officer hits a man with a baton as he tries to maintain order while migrants wait for trains at a temporary camp near Gevgelija, Macedonia, September 7, 2015. Several thousand migrants in Macedonia boarded trains on Sunday to travel north after spending a night in a provisional camp. Macedonia has organised trains twice a day to the north border where migrants cross into Serbia to make their way to Hungary. Since June, Macedonian authorities have said that more than 60,000 migrants have entered the country, and around 1,500 entered just in one day, mainly refugees from Syria. (Photo by Stoyan Nenov/Reuters)

Fighters Holly “The Lotus” Mei (L) and Teri “Feisty Fists” London train for the upcoming 'Lingerie Fighting Championships 22: Costume Brawl I' at DXG Self Defense on October 25, 2016 in Las Vegas, Nevada. The event is scheduled to feature eight bouts at 4 Bears Casino & Lodge on October 29, 2016 in New Town, North Dakota. (Photo by Ethan Miller/Getty Images)